希望這個Demo，可以給大家在視訊濾鏡製作上帶來一些靈感、避免重複造輪子。也希望大家轉載的時候帶上原文地址，算是對原創的鼓勵。

最下方有Demo地址
執行環境Xcode7.3.1

這個Demo應該是對GPUImage的總結吧，包含了視訊寫入，濾鏡資訊讀取。前面幾篇文章也分別對GPUImage中常用的功能進行了分別介紹。雖說GPUImage是開源的，但對初學者來講上手還是有一定難度的，希望可以幫助大家。

在GPUImage的探索的道路上依舊還未停止。

需求：

效果如圖 :

![這裡寫圖片描述]

Demo目錄：

 CGFloat distance = offset - attribute.center.x;
        // 越往中心移動，值越小，那麼縮放就越小，從而顯示就越大
        // 同樣，超過中心後，越往左、右走，縮放就越大，顯示就越小
        CGFloat scaleForDistance = distance / self.itemSize.height;
        // 可調整，值越大，顯示就越大
        CGFloat scaleForCell = 1 + 0 * (1 - fabs(scaleForDistance));

        // only scale y-axis
        attribute.transform3D = CATransform3DMakeScale(1, scaleForCell, 1);
        attribute.zIndex = 1;

可通過調節0 * (1 - fabs(scaleForDistance));來改變效果。

StoryBoard說明:

storyboard具備快速開發的優點，除了實時變化相對於程式碼差一點，其他的他已經很成熟、也是偉大的開發模式、在這裡也希望那些老傢伙們別固執與程式碼佈局，緊隨時代吧！
特別提示：注意Mylayout的位置 很重要

初始化相機和GPUImageview：

func setNewCameraAndGPUViewAndStart() {
        videoCamera = GPUImageVideoCamera.init(sessionPreset: AVCaptureSessionPreset640x480, cameraPosition: AVCaptureDevicePosition.Front)
        videoCamera.outputImageOrientation = UIInterfaceOrientation.Portrait
        videoCamera.horizontallyMirrorFrontFacingCamera = true
        videoCamera.horizontallyMirrorRearFacingCamera = true

        filter = SSGPUImageBeautyFilter.init()

        filterView = self.view as! GPUImageView
        filterView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill
        videoCamera.addTarget(filter as GPUImageInput)
        filter.addTarget(filterView)

        videoCamera.startCameraCapture()

    }

初始化寫入物件：

func getNewMovieWriter() {

        let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory,
                                                        .UserDomainMask, true)
        let documentsDirectory = paths[0] as String
        let filePath : String? = "\(documentsDirectory)/DBLiveTest\(currentTimeStamp()).mp4"
        movieURL = NSURL(fileURLWithPath: filePath!)


        movieWriter = GPUImageMovieWriter.init(movieURL: movieURL, size: CGSizeMake(480.0, 640.0))
        movieWriter.encodingLiveVideo = true
        if groupFilter == nil {
            filter.addTarget(movieWriter)

        }else{
            self.groupFilter?.addTarget(movieWriter)

        }
        videoCamera.audioEncodingTarget = movieWriter

    }

切換濾鏡

//換濾鏡
    func switchFilter(index: Int) {
        self.filter?.removeAllTargets()
        self.groupFilter?.removeAllTargets()
        self.currentFilterIndex = index
        let lookupImageName = self.filterModel.filterList[index].lookupImageName

        self.lookupFilter = GPUImageCustomLookupFilter.init(lookupImageName: lookupImageName)
        self.setUpGroupFilters(self.lookupFilter!)
        self.groupFilter?.addTarget(filterView)



        self.groupFilter?.addTarget(movieWriter)

    }

    func setUpGroupFilters(lookupFilter: GPUImageCustomLookupFilter) {
        self.groupFilter = GPUImageFilterGroup.init()
        self.groupFilter?.addTarget(filter)
        self.filter?.addTarget(lookupFilter)
        self.groupFilter?.initialFilters = [self.filter!]
        self.groupFilter?.terminalFilter = lookupFilter
    }

播放視訊

func playVideoAndAddPreView() {
        dispatch_async(dispatch_get_main_queue()) {

            let paths = NSSearchPathForDirectoriesInDomains(.DocumentDirectory,.UserDomainMask, true)
            let documentsDirectory = paths[0] as String
            let filePath1 : String? = "\(documentsDirectory)/DBLiveTest\(currentTimeStamp()).jpg";

            UIImagePNGRepresentation(getFirstImageFromVideo(self.movieURL))?.writeToFile(filePath1!, atomically: true);

            self.thumbURL = NSURL(fileURLWithPath: filePath1!)

            animationFlipFromRight(self.filterView)
            self.videoCamera.stopCameraCapture()

            self.playerItem = AVPlayerItem(URL: self.movieURL)
            // 建立 AVPlayer 播放器
            self.player = AVPlayer(playerItem: self.playerItem)
            // 將 AVPlayer 新增到 AVPlayerLayer 上
            self.playerLayer = AVPlayerLayer(player: self.player)
            // 設定播放頁面大小
            self.playerLayer.frame = self.view.frame
            // 設定畫面縮放模式
            self.playerLayer.videoGravity = AVLayerVideoGravityResizeAspectFill
            // 在檢視上新增播放器
            self.view.layer.addSublayer(self.playerLayer)
            // 開始播放
            self.player.play()
            self.addPreViewToSufureView()
        }
    }

儲存到相簿：

func doYouWantSaveItToAlbum(bool:Bool) {
        if bool == true {
            let library = ALAssetsLibrary()

            if library.videoAtPathIsCompatibleWithSavedPhotosAlbum(movieURL) {
                library.writeVideoAtPathToSavedPhotosAlbum(movieURL, completionBlock: { (assetURL, error) in
                    dispatch_async(dispatch_get_main_queue(), {
                        if error == nil{
                            let alert = UIAlertView.init(title: "提示訊息", message: "儲存成功", delegate: nil, cancelButtonTitle: "確定")
                            alert.show()
                        }else{
                            let alert = UIAlertView.init(title: "提示訊息", message: "儲存失敗", delegate: nil, cancelButtonTitle: "確定")
                            alert.show()
                        }
                    })
                })
            }

        }
    }

用到的全域性方法：

//翻轉動畫
func animationFlipFromLeft(view:UIView) {
    UIView.beginAnimations(nil, context: nil)
    UIView.setAnimationCurve(UIViewAnimationCurve.EaseInOut)
    UIView.setAnimationDuration(0.5)
    UIView.setAnimationTransition(UIViewAnimationTransition.FlipFromLeft, forView: view, cache: false)
    UIView.commitAnimations()
}

//翻轉動畫
func animationFlipFromRight(view:UIView) {
    UIView.beginAnimations(nil, context: nil)
    UIView.setAnimationCurve(UIViewAnimationCurve.EaseInOut)
    UIView.setAnimationDuration(0.5)
    UIView.setAnimationTransition(UIViewAnimationTransition.FlipFromRight, forView: view, cache: false)
    UIView.commitAnimations()
}

//時間戳
func currentTimeStamp()->String {
    let now = NSDate()
    let dformatter = NSDateFormatter()
    dformatter.dateFormat = "yyyy年MM月dd日 HH:mm:ss"
    print("當前日期時間：\(dformatter.stringFromDate(now))")



    //當前時間的時間戳
    let timeInterval:NSTimeInterval = now.timeIntervalSince1970
    let timeStamp = Int(timeInterval)

    return String(timeStamp)

}
//獲取視訊第一幀
func getFirstImageFromVideo(videoUrl:NSURL)->(UIImage){


    let asset = AVURLAsset(URL:videoUrl)

    let generator = AVAssetImageGenerator(asset: asset)

    generator.appliesPreferredTrackTransform=true

    let time = CMTimeMakeWithSeconds(0.0,600)

    var actualTime:CMTime = CMTimeMake(0,0)

    var image:CGImageRef!

    do{
        image = try generator.copyCGImageAtTime(time, actualTime: &actualTime)
    }catch let error as NSError{
        print(error)
    }

    return UIImage(CGImage: image)


}

模糊效果：

//新增模糊效果
    func addVisualEffectView() {
        self.effectView = UIVisualEffectView.init(effect: UIBlurEffect.init(style: UIBlurEffectStyle.Light));
        self.view.addSubview(self.effectView)
        self.effectView.frame = self.view.bounds
    }